Which focus settings should I be using for taking pictures of planes flying by on my T5i? There are three settings ONE SHOT, AI FOCUS, and AI SERVO. I've been using ONE SHOT but it doesn't seem to be focusing the greatest when taking burst shots?

Quoting AndrewMoir (Thread starter):I've been using ONE SHOT but it doesn't seem to be focusing the greatest when taking burst shots?

Well, that makes sense. During a burst, the airplane is moving relative to you. If you're on ONE SHOT, the camera isn't refocusing as the airplane moves. So the focal plane (no pun intended) stays the same distance away from your first shot to your last, while the airplane may have moved quite a bit. If you want the camera to refocus as you shoot during a burst, you have to use AI SERVO (I forget what AI FOCUS is....some combo of the two I think?).

That said, some people swear by AI SERVO, and some don't. Personally, I use ONE SHOT for almost everything. I hardly ever shoot bursts, so I just refocus before each shot. Plus, if my focal point slips off of the airplane (I use center-point only), the lens doesn't suddenly focus to infinity then have to pick up the airplane again, as it would in AI SERVO.

Either way is fine, you just have to understand what your camera is doing in each setting. Read the manual - it's actually quite informative and helpful.